The present invention relates to lighting fixtures adapted for landscape and environmental lighting applications and, more particularly, to in-, or below-ground lighting fixtures.
The use of outdoor lighting fixtures has become increasingly popular for illuminating buildings, gardens, pathways and entrance ways as the nighttime play of light on the landscape and vegetation is aesthetically pleasing. Additionally, such lighting provides enhanced security by eliminating hiding places and unobserved entry points for intruders. Outdoor lighting systems include one or more lighting fixtures which are connected to either a 12 V transformer or a standard 120 VAC line. The lighting fixtures generally include a housing, a lamp assembly having a halogen or conventional bulb and a reflector, and a lens or window. Many configurations are known for providing a variety of different lighting effects.
Landscape lighting fixtures, most of which are mounted at or above ground level are generally considered to appear somewhat incongruous with the surrounding vegetation during daylight hours, when the illumination function is not in use. Further, because of the constant exposure to the elements, above ground lighting fixtures are generally required to be made of expensive, high quality materials, such as non-corrosive metal alloys, in order to provide durability and a reasonable resistance to damage so as not to appear cheap and unkempt.
As an alternative to the above-ground placement of landscape lighting fixtures, recessed, in-ground lighting fixtures, also known as xe2x80x9cwell lightsxe2x80x9d, have gained widespread acceptance. In certain applications, the use of below-ground landscape lighting is preferable over above-ground varieties, especially in areas surrounding walkways where an above-ground element could poses a tripping hazard or in lawn areas where the use of a lawn mower presents a risk of damage to the fixture.
Despite having a number of advantages over above-ground type fixtures for certain applications, in-ground light fixtures encounter problems not typically seen in lighting fixtures of other varieties. A significant problem is the intrusion of water or other electrically conductive fluids into the subterranean receptacle housing the lighting fixture. A number of sealing techniques have been employed in the prior art. In the in-ground light fixture of Wagner, et al., U.S. Pat. No. 5,481,443, a single sealing element between the lens and the fixture housing is relied upon to provide a barrier against moisture intrusion. The U.S. Pat. No. 5,003,441 of Crowe, et al., which discloses an in-ground pop-up light fixture, makes passing mention to xe2x80x9cthe lower housing is normally sealed watertightxe2x80x9d but fails to disclose the means by which the seal is created. The well light of Porter, et al., U.S. Pat. No. 5,230,559, makes no provision for ensuring water resistance of the lighting fixture and attached wiring. The need for water resistance is of additional importance to in-ground fixtures since the light emitting surface is usually horizontal, providing a place for water to pool and increasing the chance of water-related damage. In addition, in such fixtures, the water can xe2x80x9cwickxe2x80x9d up the field wire into the fixture housing, thus imposing the need for the fixture to be water-tight from all perspectives.
A second problem experienced with below-ground light fixtures is the need to control the direction of illumination with maximum efficiency and ease for the user. A significant limitation is that the lamp is located at or below ground surface, which limits the range of illumination and convenient access to the lamp. It would be an advantage to have an apparatus where the lamp is easily accessible to the user for adjustment of beam quality and direction without compromising the water tightness or weather resistant features of the fixture.
A third, seldom addressed problem is a means for cooling the in-ground lighting fixture. Halogen and incandescent filaments generate a significant amount of radiant heat when illuminated. Being placed in-ground, the lighting fixture has limited means for providing air circulation to dissipate heat build-up within the fixture which can potentially lead to failure of the fixture due to damaged or melted components and electrical wiring as well as accelerating corrosion due to the exposure to outdoor environments. Furthermore, minerals and other residue deposited on the lens as the result of irrigation and other environmental exposure are baked on by the heat generated by the lamp. The baked-on residue obscures light output and exacerbates the tendency for heat build-up.
It would be desirable to provide an in-ground lighting fixture that provides a watertight interior environment for electrical wiring and associated elements while allowing for adjustability of the light beam. An additional cooling means for the lighting element would also be desirable. These problems and deficiencies are clearly felt in the art and are solved by the present invention in the manner described below.
It is an advantage of the present invention to provide an in-ground lighting fixture that is water-tight.
It is a further advantage of the present invention to provide an in-ground lighting fixture that allows multi-axis adjustment of the beam.
Another advantage of the present invention is to provide an in-ground lighting fixture that has means for cooling and providing air circulation for the below-ground portion of the fixture.
Still another advantage of the invention is to provide an in-ground lighting fixture that minimizes build-up on the lens that can occur from exposure of the fixture to water and dirt.
In an exemplary embodiment, the in-ground, or xe2x80x9cwell lightxe2x80x9d, fixture comprises a hollow cylindrical housing, a bezel and lens mounted at the upper end of the housing, and a lamp assembly comprising a watertight lamp enclosure containing a lamp and reflector. The lamp enclosure is secured by support brackets which extend downward from the bottom portion of the bezel to provide three-axis adjustability of the lamp. An optional mounting ring is attached at the upper end of the housing to form a flange to facilitate stable placement of the well light in the ground as well as providing an attractive frame around the fixture. The lens is retained at a shallow angle within the bezel to permit water and dirt to run off of the lens surface.
The bezel comprises a circular plate that has top and bottom portions and an outside diameter that fits within the inside diameter of the mounting ring so that the bezel is supported on top of the upper end of the housing. The bottom portion of the bezel has a first inner diameter sized to fit within the inner diameter of the housing and a second inner diameter larger than the first inner diameter to create a lip adapted to fit over the top edge of the housing. When seated, the upper surface of the bezel is flush with the upper face of the mounting ring. The bezel has a plurality of openings therethrough, including a window opening that is generally rectangular to provide access to a transparent lens that is disposed at a shallow angle relative to horizontal to guide water and dirt away from the lamp assembly, allowing the water to run off the outer edge of the lens without pooling. A plurality of radially-arranged openings provide air circulation into and out of the interior of the housing, keeping the outer lens cool. Both the mounting ring and the bezel can be made from brass, anodized or powder-coated aluminum, or any other material that provides appropriate durability and weather-resistance as well as being aesthetically pleasing.
Retained within the housing is a lamp assembly comprising a shroud portion, a window, and a base portion which enclose a lamp and reflector. A pair of lamp support brackets are provided to mount the lamp assembly to the bottom portion of the bezel. Each bracket has a flanged portion for attachment to the bezel and a straight portion which attaches to the-lamp assembly. The brackets are disposed on opposite sides of the lamp base. Axial mounting screws are inserted from either side of the lamp base into threaded bores to hold the lamp assembly in place on the brackets while defining a pivot axis for tilting the lamp at a desired angle. The flanged portion of each bracket has an elongated slot formed therein through which the mounting screws are inserted, allowing the lamp assembly to be moved along a line parallel to the length of the window, then locked in place with the mounting screws. The straight portion of each bracket has an elongated slot formed therein to allow the lamp assembly to be adjusted closer to or farther away from the lens to alter the beam spread, then locked into position by tightening the axial mounting screws. The two sets of elongated slots and the axial mounting screws combine to provide a three-axis gimble mounting that provides maximum aiming flexibility, from near horizontal, e.g., for use in illuminating signs or walls, to vertical, for use lighting, e.g., flagpoles, trees, or overhead structures.
The base portion of the lamp assembly is generally cylindrical with a first end and a second end. A watertight electrical connector sleeve extends through the side of the second end for passing electrical wires from the outside to the interior of the base portion to connect to the socket that holds the lamp. Optional epoxy potting may be used to fill in the bottom interior spacing within the base to further provide stability for the socket and water-proofing for the electrical connectors. The outer surface of the second end has a plurality of annular cooling fins extending therefrom to function as a heat sink to dissipate heat generated by the lamp. The first end of the base is threaded with external ACME screw threads with an O-ring seat formed below the lowest thread. A large gauge O-ring is disposed within the O-ring seat so that the outer diameter of the O-ring is larger than the diameter of the screw threads. A second, smaller gauge O-ring is disposed below the first O-ring, closer to the second end of the base portion, and has an outer diameter that is greater than the outer diameter of the first O-ring.
The shroud portion of the lamp assembly is generally cylindrical with a window end and a base end. The interior of the base end has internal ACME screw threads for mating with the external threads on the base portion. A smooth inner sidewall below the threaded portion contacts the large O-ring to provide a tight fit, while the interior edge of the base end is chamfered to tightly fit against the second smaller O-ring, combining to create a watertight seal between the shroud portion and the base portion. The window end of the shroud portion has a recess formed for receiving the window, or lens, with the outer face of the window flush with the edge of the window end. The window is sealed within the shroud to create a watertight seal using a latex or RTV-silicone sealant or other appropriate sealant.
When an appropriate commercially-available lamp/reflector combination is plugged into the socket in the base portion, sufficient space remains between the upper extent of the reflector and the window to insert filters, diffusers or other optical elements to modify the beam, if desired. A bias spring can be used to provide an upward bias against the reflector to keep the lamp pressed against any optical elements that might be used.
The well light of the present invention provides a highly adjustable recessed fixture that is sufficiently watertight that it can actually be used in underwater applications such as swimming pools, decorative ponds and fountains.